Advantix II For Dogs kills 98-100% of the existing fleas on dogs within 12 hours. Re-infesting fleas are killed within 2 hours with protection against further flea infestation lasting at least four (4) weeks. Pre-existing pupae in the environment may continue to emerge for six (6) weeks or longer depending upon the climatic conditions.

K9 Advantix II Dog Flea & Tick Drops remains an efficacious tick and flea treatment following a shampoo, swimming, or after exposure to rain or sunlight.

Monthly tick & flea treatment is required for optimal control and prevention of fleas and ticks.

Does not expire if package remains unopened and is stored properly according to instructions.